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Session: Radiopharmaceutical Therapy Dosimetry [Return to Session]

Commissioning of a Commercial Whole-Body Gamma Camera Image-Based Radiopharmaceutical Therapy Treatment Planning System

W Erwin1*, (1) UT MD Anderson Cancer Center, Houston, TX


SU-E-202-2 (Sunday, 7/10/2022) 1:00 PM - 2:00 PM [Eastern Time (GMT-4)]

Room 202

Purpose: To validate the calculations of a commercial radiopharmaceutical treatment planning software application (HD = Organ Dosimetry™ with Olinda/EXM® 2.0, HERMES Medical Solutions AB).

Methods: Four calculational components of the software were tested: 1) region of interest (ROI) total count value; 2) whole-body, organ and tumor ROI fraction of injected activity vs. time (FIA(t)); 3) FIA(t) exponential fit λ(s) and intercept(s), and residence time; and 4) ICRP 89 phantom equivalent dose. Input data were from six radiopharmaceutical studies: I-131-NaI, I-131-mIBG, Lu-177-DOTATATE, Sm-153-EDTMP, In-111-ibritumomab and Ho-166-DOTMP. Organs evaluated were: total body, thyroid, lungs, heart, liver, kidneys, spleen and/or bladder (depending on radiopharmaceutical). One Ho-166-DOTMP tumor was also evaluated. All results were compared to those from independent calculations.

Results: Only total count values are exportable from HD, so only whole-image rectangular and irregular ROIs could be tested. All values were identical to those obtained using ImageJ 1.52p. Most FIA(t) values were within ±2% of those calculated in Excel using scan duration (SD) normalization (a few were larger due to round off in values reported by HD). Differences as large as +12.1% and -56.7% for In-111 and Ho-166 were were observed using standard-source (SS) normalization, due to errors in HD SS ROI saving. Fit parameters were within ±5% of those calculated by GraphPad Prism 8.0, except for Sm-153-EDTMP kidneys intercepts (-25.7%) and fast-component λ's (-10.8%); but all residence times were within ±2%. All equivalent doses were within ±1% of those calculated in Excel, except for In-111 and Lu-177 patient-specific masses (-5% to +12%), due to an error in OLINDA mass-correction of ICRP 89 phantom beta self-dose (correct for legacy ORNL phantoms).

Conclusion: All HD calculations were within ±5% of independent calculations using SD normalization and reference masses. SS normalization and beta self-dose mass correction errors were reported to the manufacturer.


Nuclear Medicine, Internal Dosimetry, Treatment Planning


IM/TH- Radiopharmaceutical Therapy: Dose estimation: MIRD/deterministic

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